A study of mechanical optimization strategy for cardiac resynchronization therapy based on an electromechanical model

Area of Science:

• Cardiovascular Engineering
• Computational Biology
• Medical Imaging

Background:

• Cardiac resynchronization therapy (CRT) success depends on optimal electrode placement and atrioventricular (AV) delay.
• Quantifying dyssynchrony and resynchronization with biventricular (BiV) pacing using mechanical optimization via computational models is limited.

Purpose of the Study:

• To investigate mechanical optimization strategies for BiV pacing using a computational model.
• To determine the optimal electrode position and interventricular (VV) delay for CRT by maximizing mechanical synchrony.

Main Methods:

• A 3D electromechanical canine model of heart failure due to complete left bundle branch block (CLBBB) was utilized.
• The maximum circumferential uniformity ratio estimate (CURE) was computed for six electrode positions.
• Heart excitation propagation was simulated using a monodomain model, and mechanical asynchrony was quantified using the eight-node isoparametric element method.

Main Results:

• The optimal pacing site was identified as the left ventricle (LV) lateral wall near the equator with a VV delay of 60 ms, achieving a maximal CURE of 0.8516.
• Mechanical optimization strategies led to greater improvements in LV synchronous contraction and hemodynamics compared to electrical optimization (E(RMS)).

Conclusions:

• Mechanical dyssynchrony measures enhance the prediction of CRT responders.
• Computational modeling with mechanical optimization offers a promising approach for improving CRT outcomes.